Because of a reduction in the production quality and an increase in the number of types of semiconductors, a new tendency in semiconductor manufacturing apparatus is emerging, more particularly, in semiconductor exposure apparatuses which handle a reduced number of wafers per lot and a lot count increase. Under such condition, semiconductor manufacturing apparatuses need to efficiently switch between lots at high speed. For example, Japanese Patent Laid-Open No. 2002-217098 (FIG. 4, paragraph No. 0031) allows a semiconductor manufacturing apparatus to reserve lots to be processed, using a queue table to register the lot processing conditions and lot processing order.
Unfortunately, in Japanese Patent Laid-Open No. 2002-217098, the contents of the queue table are lost when, e.g., the semiconductor manufacturing apparatus is reactivated while lot information is registered in the queue table. Therefore, if the semiconductor manufacturing apparatus must be reactivated due to an unexpected accident, lot information needs to be re-registered in the queue table to continue the lot process. As a result, the production efficiency of the semiconductor manufacturing apparatus diminishes.